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载人航天废弃物的空间辐射防护性能研究
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作者 许峰 鲁维 +3 位作者 杨春信 国耀宇 费锦学 贾向红 《载人航天》 CSCD 北大核心 2018年第2期238-244,共7页
针对载人深空探索中的空间辐射,特别是大规模太阳粒子事件对航天员的威胁,需要在载人航天器内建立空间辐射应急防护区,为航天员在遭遇太阳粒子事件的时候提供必要的保护。考虑热融化压实技术在降低废弃物的空间占用率、高温杀菌和回收... 针对载人深空探索中的空间辐射,特别是大规模太阳粒子事件对航天员的威胁,需要在载人航天器内建立空间辐射应急防护区,为航天员在遭遇太阳粒子事件的时候提供必要的保护。考虑热融化压实技术在降低废弃物的空间占用率、高温杀菌和回收水分的同时能在不增加额外载荷的情况下为航天员空间辐射应急防护区的建设提供材料,在载人航天废弃物模型的基础上,利用Monte Carlo方法对其热融化压实产物的质子防护能力进行了计算,结合太阳粒子事件能谱和组织器官剂量计算转换因子,对不同屏蔽条件下太阳粒子事件造成航天员组织器官剂量的变化进行了研究。结果表明,在10 g/cm^2屏蔽厚度下,皮肤、脑、心脏以及红骨髓的辐射剂量都大大降低,均在剂量限值之下;除了需要对眼采取额外的局部防护措施以外,5 g/cm^2铝屏蔽+5 g/cm^2载人航天废弃物热融化压实产物基本上可以满足对太阳粒子事件的防护需求。 展开更多
关键词 废弃物 融化压实 辐射防护 太阳粒子事件
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铁路鲜活货物运输规则解释(续14)
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《铁道货运》 1998年第2期52-53,共2页
铁路鲜活货物运输规则解释(续14)铁道部《鲜规解释》编写组4.冻害和冷害“冻害”是指车内温度已降到货物(怕冻的冷却货物及新鲜水果、蔬菜)的冰点(一般为-2.5~0.5℃)之下,货物开始冻结,导致货物发生生理病害。“冷... 铁路鲜活货物运输规则解释(续14)铁道部《鲜规解释》编写组4.冻害和冷害“冻害”是指车内温度已降到货物(怕冻的冷却货物及新鲜水果、蔬菜)的冰点(一般为-2.5~0.5℃)之下,货物开始冻结,导致货物发生生理病害。“冷害”是指货物温度并未降到冰点,货物... 展开更多
关键词 冰盐混合物 鲜活货物 运输规则 融化热 加冰冷藏车 冷却货物 铁路 冻结货物 盐水 生理病害
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“及时冷”快速冷却器
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作者 池贵法 《家庭电子》 1997年第10期10-10,共1页
关键词 冷却器 融化热 冰冻饮料 吸盘
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An Experimental Study on Thermal Characteristics of Laurie Acid as a Latent Heat Storage Material during Melting Process 被引量:1
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作者 Ahmet SARI 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第2期240-243,共4页
The objective of this study was to establish the thermal characteristics of the lauric acid (95% purity) as a latent heat storage material filled in the annulus of vertical concentric double pipe during its melting pr... The objective of this study was to establish the thermal characteristics of the lauric acid (95% purity) as a latent heat storage material filled in the annulus of vertical concentric double pipe during its melting process,The temperature data were used to determine the thermal characteristics,including the temporal temperature variations and the effects of the mass flow rate and the inlet temperature of the heat transfer fluid on the heat transfer coefficient and the heat charging fraction during the melting process,The results indicated that the time to reach to heat charging fraction of 1.0 could be altered by changing the mass flow rate and the inlet temperature of the heat transfer fluid. 展开更多
关键词 lauric acid phase change material thermal characteristics melting process
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Heating and melting mechanism of stainless steelmaking dust pellet in liquid slag 被引量:1
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作者 彭及 唐谟堂 +3 位作者 彭兵 余笛 J. A. KOZINSKI 唐朝波 《Journal of Central South University of Technology》 EI 2007年第1期32-36,共5页
The heating and melting mechanisms of the pellets immersed in liquid slag were investigated, and the effect of the pellet heating and the melting conditions were studied. The results show that the dust component in th... The heating and melting mechanisms of the pellets immersed in liquid slag were investigated, and the effect of the pellet heating and the melting conditions were studied. The results show that the dust component in the pellet is melted from the surface and no metallic elements are melted before the dust component, the time for the pellet completely melted is reduced as the iron powder content increases since the metallic iron has high thermal conductivity. These are four stages of heating and melting of pellet in liquid slag, they are the growth and melt of solid slag shell, penetration of liquid slag, dissolving of dust component and melting of reduced metals. The lifetime of the solid slag shell is in the range of 7-16 s and increasing the pre-heating temperature of the pellet and the slag temperature can shorten the slag shell lifetime. The time for the dust component in the pellet to be melted completely is in the range of 20-45 s and increasing the pre-heating temperature, especially in the range of 600-800 ℃, can obviously reduce the melting time. A higher slag temperature can also improve the pellet melting and the melting time is reduced by 10-15 s when the slag temperature is increased from 1 450 to 1 550 ℃. The pellet with higher content of iron powder is beneficial to the melting by improving the heat conductivity. 展开更多
关键词 HEATING MELTING MECHANISM stainless steelmaking dust RECYCLING
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Calculation of the Heat Energy Needed for Melting of the Ice Formed from Bounded Water in the Wood
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作者 Nencho Deliiski 《Journal of Environmental Science and Engineering(B)》 2013年第3期127-134,共8页
An engineering approach for the calculation of the specific heat energy needed for melting of the ice, which is created from the freezing of hygroscopically bounded water in the wood, qbw, has been suggested. The appr... An engineering approach for the calculation of the specific heat energy needed for melting of the ice, which is created from the freezing of hygroscopically bounded water in the wood, qbw, has been suggested. The approach, together with the equation that presents it, includes mathematical descriptions of the density of frozen wood in the hygroscopic diapason, Pw, and of the specific heat capacity of the ice formed from the bounded water in the wood, cbw for the calculation of Pw, cbw and qbw according to the suggested approach a software program has been prepared in the calculation environment of Visual Fortran. Using the program computations have been carried out for the determination ofpw, cbw and qbw, of oak, pine, beech and poplar frozen wood with initial temperature in the range from -20℃ to -2℃, at which the thawing of the ice from the bounded water is completed, and with moisture content in the hygroscopic range during wood defrosting. Based on the obtained results, a very simple and easy for use equation for the calculation of qbw depending only on the wood moisture content and on the content of non-frozen water in the wood at given initial wood temperature has been suggested. 展开更多
关键词 Wood density specific heat capacity specific heat energy ice from bounded water defrosting of wood wood specie.
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Thermal state of soils in the active layer and underlain permafrost at the kilometer post 304 site along the China-Russia Crude Oil Pipeline 被引量:4
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作者 WANG Yong-ping LI Guo-yu +3 位作者 JIN Hui-jun LU Lan-zhi HE Rui-xia ZHANG Peng 《Journal of Mountain Science》 SCIE CSCD 2016年第11期1984-1994,共11页
On-site monitoring is very important for understanding formation mechanisms of frost hazards frequently occurring in pipeline foundation soils and for designing and deploying according mitigative measures in permafros... On-site monitoring is very important for understanding formation mechanisms of frost hazards frequently occurring in pipeline foundation soils and for designing and deploying according mitigative measures in permafrost regions.Significant thaw subsidence of ground surfaces along the ChinaRussia Crude Oil Pipeline(CRCOP) from Mo'he to Daqing,Heilongjiang Province,Northeast China have been observed at some segments underlain by ice-rich warm(>1.0°C) permafrost since the official operation in January 2011.Recent monitoring results of the thermal states of foundation soils at the kilometer post(KP) 304 site along the CRCOP are presented in this paper.The results indicate that during the period from 2012 to 2014,shallow soils(at the depths from0.8 to 4.0 m from ground surface) has warmed by approximately 1.0°C in the lateral range of 1.2 to 2.1 maway from the pipeline axis,and deeper permafrost(such as at the depth of 15 m,or the depth of zero annual amplitude of ground temperatures) by 0.08°C per year 4 m away from the pipe axis,and 0.07°C per year 5 m away from the pipeline axis.The results indicate an all-season talik has developed around and along the CRCOP.The thaw bulb,with a faster lateral expansion(compared with the vertical growth),enlarges in summer and shrinks in winter.This research will provide important references and bases for evaluating thermal influences of warm pipeline on permafrost and for design,construction,operation and maintenance of pipelines in permafrost regions. 展开更多
关键词 China-Russia Crude Oil Pipeline PERMAFROST Thermal regime Talik formation Thaw subsidence
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家用小型快速冷却器
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作者 陈晓虹 《现代家电》 1997年第5期27-27,共1页
日本积水化学公司研制成功了一种家用小型快速冷却器——及时冷,冰镇一罐饮料,只需90秒钟,既快捷,又方便。这种家用小型快速冷却器,利用冰的融化热,可以把接近室温25℃左右的饮料,在短短的90秒钟内,快速地冷却到冷饮的温度8℃。通常要... 日本积水化学公司研制成功了一种家用小型快速冷却器——及时冷,冰镇一罐饮料,只需90秒钟,既快捷,又方便。这种家用小型快速冷却器,利用冰的融化热,可以把接近室温25℃左右的饮料,在短短的90秒钟内,快速地冷却到冷饮的温度8℃。通常要冷却到这个温度,需在冰箱冷藏室中放置2~3个小时,放在冷冻室中,也需要大约40分钟。该家用小型快速冷却器的结构十分简单,使用也很方便。只要把想要冷却的罐装饮料,利用吸盘吸附在马达上,然后,在放入冰块的装置中,不停地旋转即可。所谓融化热,就是冰在融化时,从周围吸取的热量。 展开更多
关键词 快速冷却器 研制成功 融化热 家用 饮料罐 小型 罐装饮料 化学公司 盘吸附 近室温
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Constructal entransy dissipation rate minimization of a rectangular body with nonuniform heat generation 被引量:8
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作者 FENG HuiJun CHEN LinGen +1 位作者 XIE ZhiHui SUN FengRui 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第9期1352-1359,共8页
Based on construtal theory, a nonuniform heat generation problem in a rectangular body is investigated in this paper. Entransy dissipation rate(EDR) is taken as the optimization objective. The optimal body shapes with... Based on construtal theory, a nonuniform heat generation problem in a rectangular body is investigated in this paper. Entransy dissipation rate(EDR) is taken as the optimization objective. The optimal body shapes with constant and variable widths of the high conductivity channel(HCC) are derived. For the rectangular first order assembly(RFOA) with constant cross-section HCC, the shape of the RFOA and width ratio of the HCCs are optimized, and the double minimum EDR is obtained. The heat transfer performance of the RFOA becomes worse when the nonuniform coefficient increases. For the RFOA with variable cross-section HCC, the EDR of the RFOA can be minimized for four times. Compared the optimal construct based on minimum EDR of the RFOA with that based on minimum maximum temperature difference, the shape of the former optimal construct is tubbier, and the average temperature difference is lower. In the practical design of electronic devices, when the thermal safety is ensured, the constructal design scheme of the former optimal construct can be adopted to improve the global heat transfer performance of an electronic device. 展开更多
关键词 constructal theory entransy theory nonuniform heat generation rectangular body generalized thermodynamic optimization
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Superheating and melting behaviors of Ag clusters with Ni coating studied by molecular dynamics and experiments
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作者 徐枫亭 钟健 +1 位作者 金朝辉 卢柯 《Science China(Technological Sciences)》 SCIE EI CAS 2001年第4期432-440,共9页
Using molecular dynamics with embedded-atom-type interatomicpotentials, we simulated the melting behavior of a spherical Ag3055 cluster coated with Ni. The semi-coherent Ag/Ni interface formed at low temperatures acts... Using molecular dynamics with embedded-atom-type interatomicpotentials, we simulated the melting behavior of a spherical Ag3055 cluster coated with Ni. The semi-coherent Ag/Ni interface formed at low temperatures acts as an effective barrier against the surface melting and leads to a substantial superheating of the Ag cluster. The melting point was found to be about 100 K above the equilibrium melting point of the bulk Ag crystal (1230 K±15 K) and about 290 K above that (1040 K) of the free Ag3055 cluster. A superheating of 70 K was observed in the high-temperature differential scanning calorimetry measurement for Ag particles with a mean size of 30 nm embedded in Ni matrix prepared by means of melt-spinning. Melting is initiated locally at the defective interfacial area and then propagates inwards, suggesting a heterogeneously nucleated melting event at the Ag/Ni interface. 展开更多
关键词 superheating and melting semi-coherent interface heterogeneous nucleation theory for melting molecular dynamics high-temperature DSC
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